How to list vertices coordinates from selected edge
This will display the  coordinates of the selected vertices of the selected object  ( you have the local and the world coordinates as @poor have noted )

import bpy

obj = bpy.context.object
bpy.ops.object.mode_set(mode = 'OBJECT')
#all selected vertices indecies
verts_ind = [i.index for i in obj.data.vertices if i.select]
bpy.ops.object.mode_set(mode = 'EDIT')

for i in verts_ind :
    local_co = obj.data.vertices[i].co
    world_co = obj.matrix_world * local_co
    print(world_co)